Transprotection of acetals to bis(methoxyphenyl)methyl (BMPM) ethers can be efficiently achieved in the presence of copper dibromide as catalyst in acetonitrile at room temperature. Acetals are conveniently and selectively converted to the corresponding mono-protected diol with bis(methoxyphenyl)methyl isopropyl ether (BMPMOiPr) as the reagent. This new practical reagent allows the BMPM transfer to 1,3-dioxolanes or 1,3-dioxanes under copper catalysis. The reaction conditions are also very mild and tolerant to various functional groups, including other protecting groups.

Copper(I)-zeolites, especially copper(I)-ultra stable Y zeolite (USY), are very efficient heterogeneous catalysts for the coupling of functionalized 1-bromoalkynes and various nitrogen derivatives. Under these conditions, sulfonylated alkyl- or arylamines and various N-heterocycles, such as oxazolidinones or indoles, could be efficiently transformed into the corresponding N-alkynyl derivatives. However, imidazoles gave addition products rather than coupling products. The reaction conditions proved compatible with a variety of functional and protecting groups. Such zeolitic catalysts can be recycled and reused at least five times without significant deactivation. Low catalyst loading could be used (4 mol%) and as low as 0.8 mol% of this heterogeneous copper catalyst still gave good conversion and yields.

 

 

The community of nematodes (Nematoda: Secernentea) in groves of North East Algeria, has been the subject of regular observations of September 2011 to May 2012. Sampling and extraction of nematodes by the buckets technique are conducted following the method of Baermann. The sampling groves are composed by olive trees (Olea europea: Oleaceae) from four varieties: Chemlal, Sigoise, Frontoï and Sévillane. We identified a total of 531 individuals. The systematic inventory revealed 14 genus of Nematoda, belonging to 10 families and 3 orders. The Tylenchida and Dorylaimida are the best represented orders. They represent 92.85% of the total community of all identified nematodes, while Aphelenchida represent only 7.15%. The genus Pratylenchus records alone 54.75% on the Sévillane variety and 33.02% on the Frantoi variety. The most represented genus on Sigoise and Chemlal varieties is Meloidogyne with respectively 43.24% and 30.43%. Grove of Sévillane variety hosts the highest abundance of nematodes with 57.44%; against only 19.96%, 13.94% and 8.66%, respectively, for the varieties Frantoi, Sigoise and Chemlal. Depending on the seasons, nematodes are more abundant in autumn (88.52%) than in winter (8.66%) and the spring (2.82%). Pratylenchus and Meloidogyne are noted with large numbers, especially in winter.

Transprotection of acetals to bis(methoxyphenyl)methyl (BMPM) ethers can be efficiently achieved in the presence of copper dibromide as catalyst in acetonitrile at room temperature. Acetals are conveniently and selectively converted to the corresponding mono-protected diol with bis(methoxyphenyl)methyl isopropyl ether (BMPMOiPr) as the reagent. This new practical reagent allows the BMPM transfer to 1,3-dioxolanes or 1,3-dioxanes under copper catalysis. The reaction conditions are also very mild and tolerant to various functional groups, including other protecting groups.

Copper(I)-zeolites, especially copper(I)-ultra stable Y zeolite (USY), are very efficient heterogeneous catalysts for the coupling of functionalized 1-bromoalkynes and various nitrogen derivatives. Under these conditions, sulfonylated alkyl- or arylamines and various N-heterocycles, such as oxazolidinones or indoles, could be efficiently transformed into the corresponding N-alkynyl derivatives. However, imidazoles gave addition products rather than coupling products. The reaction conditions proved compatible with a variety of functional and protecting groups. Such zeolitic catalysts can be recycled and reused at least five times without significant deactivation. Low catalyst loading could be used (4 mol%) and as low as 0.8 mol% of this heterogeneous copper catalyst still gave good conversion and yields.

 

 

The exposure to nickel chloride (NiCl₂) can cause hematotoxicity and hepatotoxicity and canaffect development. The present study pertains to the protective effect of selenium (Se) against NiCl₂-induced toxicity in preimplanted Wistar albino rats. The subcutaneous (s.c.) administration of 25 or 50 mg/kg of NiCl₂ to Wistar albino rats on day 3 of gestation induced an immediate and significant decrease in maternal body weight and anemia 2 days after treatment. In addition, an increase in plasma aspartate aminotransferase (AST) was observed. These effects were maintained on day 20 of gestation. Moreover, a significant increase in plasma alanine aminotransferase (ALT) levels was observed with the administration of 25 mg/kg of NiCl₂. Conversely, administration of 50 mg/kg of NiCl₂ by s.c. injection increased erythropoiesis at day 20 of gestation and decreased platelets counts. In addition, administration of 100 mg/kg of NiCl₂ markedly reduced the maternal body weight and number of live fetuses and increased fetal loss, predominantly at the end of the experimental period. All dose levels of NiCl₂ caused an alteration in the hepatic histoarchitecture. When 0.3-mg/kg Se was injected s.c. with 100-mg/kg NiCl₂, the levels of plasma AST and ALT and the structure of the liver were restored. Administration of 20 mg/L/day of NiCl₂ in the drinking water significantly reduced the maternal body weight at day five of gestation as well as erythropoiesis during the exposure period. The present study suggests that Se can counteract the nocuous effect of nickel on the liver; however this antioxidant did not prevent alterations in development and erythropoiesis. © 2011 Wiley Periodicals, Inc. Environ Toxicol 2013.

Primary and secondary silylated alcohols are easily converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr2 as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

 

Graphical abstract

Primary and secondary silylated alcohols are easily and rapidly converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr₂ as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

 

Primary and secondary silylated alcohols are easily converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr₂ as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

Graphical abstract

Primary and secondary silylated alcohols are easily and rapidly converted to bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr₂ as catalyst in acetonitrile at room temperature. Various other protecting groups are compatible with this mild and convenient process.

Cancer register in the Wilaya of Batna is a population based register that covers 1,173,852 inhabitants in 2011 (estimation made with a rate of population increase of 1.58% beginning from the 2008 RGPH census). A total number of 768 new cases has been identified, which represents a standardized incidence of 78.2 cases per 100,000. The most prevalent cancers in males were lung cancer (12.2 cases / 100,000 inhabitants), colorectal cancers and bladder cancers, respectively. In females, breast cancer was largely the most prevakent type, representing 30% of the total cancers, followed by colorectal cancers and thyroid cancer. In children aged 0 to 14, the standardized prevalence was 1.9 per 100,000 inhabitants, largely dominated by malignant blood and lymphoid organs cancers.

Objective: Potassium dichromate (K₂Cr₂O₇) is a potent pollutant for human and animal health. The purpose of the current work is to compare the effect of K₂Cr₂O₇ using variations in the dose, route of administration and duration of exposure in male and female Wistar albino rats and to research the interaction of chromium and selenium with a special focus on hematopoiesis. 

Materials and methods: K₂Cr₂O₇ was subcutaneously administered alone (10, 50 and 100 mg/kg body weight) or K₂Cr₂O₇ (10 mg/kg) in association with selenium (0.3 mg/kg) was administered to female Wistar albino rats. Male rats received in their drinking water K₂Cr₂O₇ (30 mg/L/day) alone or in association with Se (0.3 mg/L/day) for 20 consecutive days. The hematological parameters were evaluated on days 3, 6 and 21 after subcutaneous (sc.) treatment in female rats and on days 10 and 20 after oral administration in male rats. 

Results: K₂Cr₂O₇₋ induced during the first three days a significant (p < 0.05) dose-dependent decrease in the number of erythrocytes, platelets, leucocytes, lymphocytes and the hematocrit levels, and a dose-dependent increase in the number of granulocytes and monocytes. In the drinking water, chromium sc. significantly decreased the number of leucocytes and lymphocytes on day 10 after treatment and elevated the number of granulocytes and monocytes 20 days later. Selenium sc. counterbalanced the hematotoxic effects of chromium in female rats. 

Conclusion: These results suggest that the selenium has a protective role against the hematotoxicity of subcutaneous chromium in female Wistar rats.

Hexavalent chromium is a potent toxic agent. It has been found to be carcinogenic in human and animal. The purpose of the current work is to compare the effect of potassium dichromate (K₂Cr₂O₇) using variations in the dose, route of administration, and duration of exposure in male and female wistar albino rats with special focus on hematological parameters. K₂Cr₂O₇ was administered either in the drinking water with a dose of 30 mg/l for 20 consecutive days to male wistar albino rats, or as a single dose subcutaneously (s.c) at 10, 50 and 100 mg/Kg body weight (b w) to female wistar albino rats. Control groups received NaCl 0.9% (0.3 ml s.c), or drinking distilled water. Haematological parameters were recorded on day 3, 6, and 21 after subcutaneous exposure, or on day 10 and 20 after oral treatment. 10 mg/Kg b w of K₂Cr₂O₇ given subcutaneously induced during the first three days a marked decrease in the number of erythrocytes (-6%) of leucocytes (-30%) of platelets (-48%) and of hematocrit values (-15%), while the number of granulocytes is augmented (+124%) in comparison with control. Hemoglobin concentration and lymphocyte counts decreased markedly on day 6 after exposure. Chromium 50 mg/Kg b w, s.c mainly affected during the first three days the leucopoietic indices inducing leucopoenia (-55%), lymphopoenia
(-57%), monocytosis (+104%), granulocytosis (+204%), and thrombocytosis (+38%) if compared with control, while the erythrocytic counts and hemoglobin concentration decreased from day 6 (-22%) and (-21%) respectively until day 21 (-41%) and (-36%) respectively, and hematocrit values decreased at the end of experiment (-36%) in comparison with control. The higher dose of chromium (100 mg/Kg b w, s.c) reduced during the first three days the number of erythrocytes (-20%), platelets (-20%), total leucocytes (-55%), lymphocytes (-59%) and augmented the number of monocytes (+56 %), and granulocytes (+166%), while on day 6 the number of platelets augmented (+27%) in comparison with control. In drinking water, 30 mg/l of chromium given to male wistar albino rats had no effect on all erythropoietic parameters studied with the exception of the elevation (+21%) in platelet counts at the end of exposure, while the number of lymphocytes and total leucocytes were significantly reduced on day 20 after exposure (-37%) and (-37%) respectively. Conversely, the number of granulocytes and monocytes markedly increased on day 10 after exposure (+42%) and (+22%) respectively if compared with control. Short-term exposures to low dose of K₂Cr₂O_7, s.c induce in female wistar albino rats erythrocytopenia, thrombocytopenia, leucopoenia, lymphopaenia, granulocytosis, monocytosis, and a decrease in hematocrit values and hemoglobin concentration while in drinking water chromium was susceptible to affect in male rats the immune response inducing leucopoenia, lymphopoenia, monocytosis, and granulocytosis, while this oral route of exposure had no effect on erythropoietic parameters.

Several reports have suggested that soluble salts nickel may affect on hematopoiesis and development. In this study female Wistar albino rats (180-300g) received NiCl2, 6H2 O, subcutaneously (25, 50 and 100 mg/kg body weight (b w) or in drinking water (20 mg/100 ml). Selenium (0.3 mg/kg b w, s.c.) was combined to NiCl2 (100 mg/kg b w, s.c.). Control groups received NaCl 0.9% (0.3 ml s.c) or drinking distilled water. All groups of rats were injected on day 4 of pregnancy in pre-implantation period. Haematological parameters were recorded on day 6 and 21 of pregnancy. Developmental parameters were assessed on day 21 of pregnancy. 25 mg/kg b w, of NiCl2 s.c, induced on day 6 an immediate and significant decrease in erythrocyte counts, hematocrit values, and haemoglobin concentrations. This depletion was maintained on day 21 of pregnancy compared to control values.On other hand 50 mg/k b w, NiCl2, s.c, reduced on day 6 of pregnancy the erythrocyte counts, hematocrit values and platelets counts. Inversely, on day 21 this dose elevated the erythrocyte counts, hematocrit values and haemoglobin concentrations ,with depletion of the platelets counts compared to control values. In group introduced 100 mg/kg b w, of NiCl2, s.c had no effect on all haematological parameters studied. NiCl2, significantly reduced the maternal body weight on day 6 and 21 of pregnancy in a dose – dependent manner in rats treated subcutaneously and in drinking water compared with control values. NiCl2, s.c. (100 mg/kg b w) markedly reduced the number of live fetuses and elevated the number of abortions on day 21 of pregnancy compared to control values. NiCl2, s.c or in drinking water had no effect on fetal body weight. Selenium (0.3 mg/kg b w, s.c.) combined to NiCl2 (100 mg/kg b w, s.c.) did not improve the effect of NiCl2.

Theffects' in vivo of acetorphan, an _enkephalinase inhibitor and naloxone, an opiate antagonist on the - - oxytocin- induced myometrial mechanical activity were studied at day 21 of pregnancy in rats. Acetarpban" I 10 mg kg -1 (i.v.) increased (344%) spontaneous uterine contractions duration only at 0-10 min period, but - did not modify amplitude. This increase in the duration was blocked by naloxone 5 mg ks -1, which had no effect on the amplitude or duration of contractions when given alone. Oxytocin (~T), I, 10 and I 100 mIU (i.v.) stimulated in a dose dependent manner, spontaneous uterine contractions duration but did not alter the amplitude of contractions. Blocking the opioid peptides by naloxone, 5 mg kg -1 (s.c.) injected --10min before OT strongly potentiated the effect of the lowest dose of OT (1 mlU) b-yabout of 59&Ofn and doubled the amplitude of contractions during the 30 min observation period. When acetorphan, 10 mg kg _-1 (i.v.) administered 30 min before the lowest dose of OT studied, 1 mID (i.v.), It induced a slight increase by .about 88% in uterine contractions duration produced by OT alone, The amplitude remained unchanged. These -results suggested that uterine contractions induced by OT in late pregnancy in rats might be regulated by enkephalinergie and enkephalinasic systems